Binding and locking device for holding sheets of material



Nov. 26, 1968 SCHWARTZ 3,412,734

BINDING AND LOCKING DEVICE FOR HOLDING SHEETS OF MATERIAL Filed Nov. 18, 1966 2 Sheets-Sheet 1 Nov. 26, 1968 M. SCHWARTZ 3,412,734

BINDING AND LOCKING DEVICE FOR HOLDING SHEETS OF MATERIAL 2 Sheets-Sheet 2 Fild Nov. 18, 1966 56 FIG. 6

FIG. IO

INVENTOR.

MAX SCHWARTZ United States 3,412,734 BENDING AND LOCKING DEVICE FGR HGLDING SHEETS OF MATERIAL Max Schwartz, 1210 N. Rowan Ave, Los Angeles, Calif. 90063 Filed Nov. 18, 1966, Ser. No. 595,452 3 Claims. (Cl. 129-18) ABSTRACT OF THE DISCLOSURE The specification discloses a binding and locking device adapted to hold similar rear edges of a plurality of thin sheets of material in a manner simulating the binding of a book and to do so in a quick engageable, positive locking and yet easily disengageable manner, and further provided with vertically spring biased keeper means adapted to hold the rear edges of the thin sheets of material in firm abutment with each other even though less than the full normal amount adapted to be mounted is carried by the binding and locking device. Additionally, the spring biased keeper aids in the positive locking of the rear edges of the thin sheets of material in the binding and locking device and, in one form of the invention, provides the major means for accomplishing this and, in another form of the invention, is arranged to be operated by additional locking means so as to be effectively moved out of engagement with the rear edges of the sheets of material when the locking means is unlocked, and Vice versa.

Generally speaking, the present invention relates to a binding and locking device for one or more sheets of material adapted, when binding and holding more than one sheet of material, to positively position them in similar surface-area-contiguous and coextensive adjacent relationship (which is usually a superimposed relationship when the device is positioned in a horizontal orientation).

The invention is particularly well adapted for mounting a plurality of thin sheets of paper or paper-like material in a binder or holder in a manner defining what may be termed a notebook, or the like. In this preferred form of the invention, each of the sheets adapted to be held by the binding and locking device may be of paper or similar material and does not need to have any special stiffening or reinforcing means along a fastening edge thereof (the edge adapted to be engaged by the binders mounting post means referred to hereinafter) and, thus, does not require any expensive modification of paper for use in appropriately mounting it in the hinder or holder of the present invention. In fact, all that is needed is to properly die-cut the paper along the fastening edge thereof so as to cut out and define one or more (in one preferred form of the invention, a pair of longitudinal spaced) inwardly and laterally directed groove means, each having an inner offset retaining portion which is retainingly receivingly cooperable with respect to the mounting or fastening post means (referred to hereinafter) of the binding and locking device of the present invention.

It will be understood that such die-cutting of the fastening edge of the paper does not add any expense in excess of that involved in punching the conventionally provided two, three, or more holes along the fastening edge of a prior art piece of paper adapted to be mounted in a conventional prior art notebook of the multiple split-ring type.

Additionally, it should be noted that the invention is provided with novel pressure-applying keeper means adapted to provide for effective retaining engagement of the binding, holding, and locking device with respect to paper of the type referred to hereinbefore having retaining 3,4l2,734 Patented Nov. 26, 1968 groove means of the type referred to hereinbefore and quite irrespective of the number of sheets of such paper held by the binding and holding device-that is, one sheet or many sheets will be equally as well retained because of the fact that the keeper means operates in a manner such as to optimize the function of the retaining groove means carried by the fastening edge of the paper despite the fact that the fastening edge of the paper has not been provided with additional reinforcement means and is relatively flexible and compliant, which characteristics, in the absence of the keeper means, would tend to render the retaining groove means virtually ineffective for positive retention of a plurality of sheets of paper.

It is a further object of the present invention to provide a binding and locking device which is not in all forms thereof limited to holding thin sheets of paper-like material whereby to effectively comprise a notebook. In certain modifications of the invention, it may hold other types of thin-sheet material, such as swatches of fabric or fabric-like material, as in a salesmans sample folder, or the like. However, the most advantageous form of the invention known at the present time is that form first mentioned above adapted to retain a plurality of sheets of paper and effectively comprising a notebook.

It is a further object of the present invention to provide a notebook having an adjustable effective capacity-- that is, which is capable of retaining and holding a greater or lesser number of sheets of paper, or the like, and capacity-changing means is effectively included in this form of the invention for this purpose.

With the above points in mind, it is an object of the present invention to provide a device of the character referred to herein generically and/or specifically, and which may include any or all of the features referred to herein, either individually or in combination, and which is of extremely simple, inexpensive, easy-to-assemble, and easy-to-disassemble construction suitable for ready mass manufacture, assembly, and distribution at relatively low cost per item, both as to initial tooling cost and as to the per-unit production cost per item, whereby to be conducive to widespread production, distribution, and use of the invention for the purposes outlined herein.

Further objects are implicit in the detailed description which follows hereinafter (which is to be considered as exemplary of, but not specifically limiting, the present invention), and said objects will be apparent to persons skilled in the art after a careful study of the detailed description which follows.

For the purpose of clarifying the nature of the present invention, one exemplary embodiment of the invention is illustrated in the hereinbelow-dcscribed figures of the accompanying two drawing sheets and is described in detail hereinafter.

FIG. 1 is a reduced-size perspective view illustrating one exemplary form of the present invention wherein it comprises a binding and locking device for holding a plurality of thin sheets of paper, or the like, and thereby effectively comprises a notebook with all of the sheets of notebook paper being held in a readily releasable, superimposed manner. The near or top cover of the binding and locking device is partially broken away and removed from FIG. 1 and its normal location is indicated by the phantom lines. This is done so that the remainder of the device can be more readily seen.

FIG. 2 is a fragmentary cross-sectional view taken substantially on the plane and in the direction indicated by the arrows 22 of FIG. 1, which plane passes directly through one of the attachment locations at the position of one of the two binding post means (it being understood that the other one is of similar construction). The top or front cover of the binding and locking device (which is 3 absent from FIG. 1) is included in FIG. 2 and is shown fragmentarily in cross-section.

FIG. 3 is a fragmentary view taken substantially along the plane and in the direction indicated by the arrows 3-3 of FIG. 1.

FIG. 4 is a fragmentary cross-sectional view taken substantially along the plane and in the direction indicated by the arrows 44 of FIG. 1. However, only the top left portion is in section; the rest of the view being in end elevation. The slidable movable left side wall comprising the transverse-movement-immobilizing means is shown in full or solid lines in its normal retracted locking relationship and is shown in broken lines in its telescopically extended, unlocked relationship.

FIG. 5 is an enlarged fragmentary elevational view taken substantially along the plane and in the direction indicated by the arrows 5-5 of FIG. 3 and illustrates one exemplary form of vertical extension locking means representative of the two similar such vertical extension locking means illustrated in the exemplary form of the invention shown.

FIG. 6 is a fragmentary view taken substantially along the plane and in the direction indicated by the arrows 6-6 of FIG. 4.

FIG. 7 is a fragmentary, partially broken-away view taken substantially along a plane similar to that of the cross-sectional portion of FIG. 4, but extending completely across the binding and locking device (with the central portion removed) and illustrates the vertical extension means of the capacity-changing means of the exemplary form of the invention which makes it possible to vertically extend the side walls (and, also, the intervening mounting post means) so as to vertically enlarge the receiving recess means into which the fastening edges of the sheets of paper are inserted for mounting on the fastening post means, thus making it possible to mount a great many more sheets of paper than would be the case without the provision of the capacity-changing means including the vertical extension means, which is shown in broken lines in extended relationship in FIG. 7 and is shown in solid lines in retracted relationship in FIG. 7.

FIG. 8 is a left end elevational view taken substantially along the plane, and in the direction indicated by the arrows 8-8, of FIG. 7.

FIG. 9 is a fragmentary view taken substantially along the plane and in the direction indicated by the arrows 9-9 of FIG. 4.

FIG. 10 is an exploded perspective view of an exemplary one of the two controllably operable constriction means or locking means shown in cooperative lockable and unlockable relationship with respect to the vertical extension means which makes it possible to vertically expand (and/or contract) the size of the receiving recess means into which the fastening edges of a plurality of sheets of notebook paper are adapted to be placed, thus making it possible to change the paper-holding capacity of the complete device.

Generally speaking, the preferred form of the invention, comprising a binding and locking device taking the form of a notebook, includes end wall means, such as is generally designated at (which will be referred to hereinafter) and which includes a pair of vertically directed, overlapped wall portions 22 and 24, which is to facilitate capacity changing of the entire device, as will be described in greater detail hereinafter.

The end wall means 20 is provided with a pair of spaced and usually substantially parallel top and bottom walls 26 and 28 similarly projectingly connected with respect to the end wall means 20 and usually in substantially perpendicular relationship with respect thereto so that the end wall means 20, the top wall 26, and the bottom wall 28 together define what might be termed receiving recess means in the region generally designated by the reference numeral 30 and into which the inner fastening edges 32 of a plurality of sheets of material such as paper, or the like, as designated at 34, are adapted to be inserted in order to be locked and held by the binding and locking device in a notebook-like fashion.

It should be noted that each of the top and bottom walls 26 and 28 actually is provided with a slightly offset and forwardly extended portion comprising the corresponding front or top cover 26c and rear or bottom cover 280. Said top and bottom walls 26 and 28, the front and rear cover portions 26c and 28c thereof, and the end wall means 20 may be made of any suitable binding material conventionally used in the book-binding art or any other material suitable for the purposes of the present invention.

The top and bottom walls 26 and 28 are effectively interiorly reinforced by, and structural strength is imparted to the complete binding and locking device by, the provision of additional or auxiliary structurally strong, inner walls 33 and 36 immediately inside of the top and bot tom walls 26 and 28, respectively, and normally in inner surface contiguous relationship or contact therewith.

Said structurally strong, auxiliary inner walls 33 and 36 have side wall portions 38 and 40 at the right and left sides thereof, respectively, when the apparatus is in the position shown in FIG. 1 (or FIG. 7), which imparts rigidity to the complete binding and locking device by reason of the provision of the four structurally strong, inner walls 33, 36, 38, and 40.

The device is provided with mounting means for mounting the sheets of paper 34 and taking the form of mounting or fastening post means connected between the auxiliary walls (by which is meant both the top and bottom walls 26 and 28 and the structural inner wall portions 33 and 36 immediately inside thereof), with the fastening post means :being spaced outwardly from the end wall means 20 and usually substantially parallel thereto so as to extend vertically through the receiving recess means 30. In the example illustrated, there are two such fastening post means, each generally designated by the reference numeral 42, and it will be noted that the details of the connection of upper and lower ends thereof with respect to the auxiliary walls will be described in greater detail hereinafter.

The binding and locking device of the present invention is also provided with transverse-movement-immobilizing means for locking each fastening edge 32 of each sheet of paper 34 in fully engaged relationship such as is clearly shown in FIG. 1.

In the exemplary form of the invention illustrated, the transverse-movernent-immobilizing means referred to above actually comprises the previously mentioned left side wall 40, which is controllably extendably and retractably mounted (in other words, slidably mounted for lateral extention and retraction) with respect to the top and bottom auxiliary walls 33 and 36, and the slidable mounting thereof together with said end wall may be said to define the above-mentioned transverse-movementimmobilizing means, which is generally designated by the reference numeral 44.

This slidable mounting of the transverse-movementimmobilizing means 44 which may also be termed a side wall abutment means, with respect to said top and bottom inner walls 33 and 36, is accomplished by the provision of what might be termed telescopic extension means 46 which, in each case, includes an outer fiat hollow rectanguar horizontal sleeve 48, which may or may not be slotted and open along the center of the inner side thereof and which slidably receives and carries within the inner opening 50 thereof the horizontal tongue member 52. It will be noted that in each case-that is, at both the top and bottom of the transverse-movement-immobilizing means 44-the tongue horizontal member 52 is connected to the left side wall member 40 and, in the case of the top tongue member 52, it is integral with an exterior vertical sleeve portion 54 thereof while the horizontal sleeve portion 48 of both the top and bottom inner structural walls 33 and 36 is attached to and effectively comprises the remainder of the corresponding top or bottom wall 33 or 36, respectively, thus providing the upper and lower telescopic extension structures generally designated by the reference numeral 46. Of course, both the upper and lower horizontal tongue members 52 are longitudinally slotted, as indicated at 55, around each mounting post means 42.

The above-described structure makes it possible to move the left side wall abutment means 44 into the solidline position shown in FiG. 4 where it is immediately adjacent to the left (as viewed in FIG. 4) edges 56 of the sheets of paper 34 so that they cannot be moved more than a very slight distance toward the side wall abutment means 40 until they come into travel-limiting contact therewith. This will prevent the removal of the sheets of paper 34 because of the fact that each of the fastening edges 32 thereof has a retaining groove means, such as generally designated at 58, which includes an entry opening 68, an inwardly directed neck portion 62, and an inner offset laterally directed retaining portion 64 in which the corresponding one of the two mounting post means 42 is adapted to be positioned, as is most clearly shown in respect to one of same in FIG. 9.

In other words, a direct outward pull in the direction of the arrow 66 of FIG. 9 applied to the sheet of paper 34 cannot remove the sheet because the mounting post 42 is in the inner offset retaining portion 64 of the retaining groove means 58, and it is apparent that it is necessary to first move the sheet of paper 34 in the direction of the arrow 68 if the sheet of paper 34 is to be removed from the mounting post means 42 and yet it is precisely movement in the direction of the arrow 68 which is positively prevented by the transverse-movementimmobilizing means 44 when it is in the retracted, closed, locked relationship best shown in FIG. 4 in solid lines.

It will readiy be understood that, if the side wall abutment means 44 is manually grasped and leftward force is applied in the direction of the arrow 70 of FIG. 4, to an extent such as to overcome the frictional force normally holding said side wall abutment means 44 in the closed, locked, retracted relationship shown in solid lines in FIG. 4, it can be telescopically extended into an extended unlocked relationship such as is clearly shown in broken lines in FIG. 4, which will allow sufiicient clearance space to move the sheets of paper 34 in the direction indicated by the arrow 68 of FIG. 9 or the arrow 70 of FIG. 4 to an extent such as to disengage each of the two mounting posts 42 from the two corresponding retaining groove means 58. This will, of course, allow the sheets of paper 34 to be removed completely from the device.

However, the removal of the paper 34 from the binding and locking device in the manner described above is further facilitated by reason of the fact that movement of the side wall abutment means 44 into the extended unlocked relationship shown in broken lines in FIG. 4 also causes vertical retraction of the pressure-applying keeper means 72 from the operative position shown in solid lines in FIG. 4 into the temporarily inoperative position shown in broken lines in FIG. 4. Incidentally, in this connection, it should be noted that when the side wall abutment means 44 is in the retracted closed and locked relationship shown in solid lines in FIG. 4, said pressureapplying keeper means 72 acts to press downwardly on the top surface of the uppermost sheet of paper 34 in a manner such as to prevent vertical separation of the fastening edges 32 of the plurality of sheets of paper 34-in other words, such as to hold sheet-fastening edges 32 closely together in the manner of a conventional book binding. This is desirable because of the fact that the fastening edge 32 of any individual sheet of paper 34 has no independent reinforcing or stiffening and, therefore, is relatively compliant and weak and, if it were not vertically restrained by the keeper means 72, it would be found quite easy to inadvertently and unintentionally remove a sheet of paper by physically damaging the fastening edge portion between the inner offset portion 64 of the groove means 58 and the inner fastening edge thereof in what might be termed a fastening tab portion thereof, as best shown at 74 in FIG. 9. However, as long as the keeper means 72 presses the fastening edges 32 of all of the sheets of paper 34 firmly together, this is extremely unlikely to happen.

While the keeper means 72 may assume a variety of different constructions and mountings, one exemplary and highly advantageous form is shown in the figures of the dnawirrg wherein it comprises a resilient spring finger member 76 slotted as indicated at 78 so as to allow the through passage of the left mounting post means 42 and having a rear end portion 80 fastened by rivets 82 to the upper horizontal tongue member 52 of the transversernovement-immobilizing means 44 so that it will move leftwvardly or rightwardly therewith and, by cooperation with the corresponding biasing loop member 84 carried by the upper horizontal sleeve member 48, will be caused to move between its free downward operative position as shown in solid lines in FIG. 4 and its temporarily inactivated position as shown in broken lines in FIG. 4.

The preferred form of the invention is provided with capacity-changing means which may also be said to con1- prise vertical extension means, such as generally indicated at 86 and which is shown as effectively comprising a tongue-andagroove type of vertical extension means which \allows the vertical space between the top and bottom inner walls 33 and 36 (and correspondingly the outer top and bottom walls 26 and 28) to be adjusted into whatever size is needed to accommodate a particular number of sheets of paper 34. It will be noted that each of said verticlal extension means 86 comprises the previously mentioned vertical outer sleeve portion 54 which is connected to the upper wall member 33 (to the sleeve 48 thereof at the right end thereof and to the tongue member 52 at the left end thereof) and that the previously mentioned vertical inner tongue member 88 is similarly connected to the bottom wall member 36. This makes it possible to move the upper wall 34 and the overlying wall 26 upwardly from a solid-line position such as is shown in FIG. 7 into an upwardly extended broken-line position such as is shown in FIG. 7 and to then lock the apparatus in said positions by controllable operation of the constriction means 90 which comprises a manually gnaspable head member 92, a shaft portion 94 extending through the slot 96 and hole 98 and cooperating with an inner mating element 100 which is carried by the tongue member 88. When the head member 92 is tightened, it will abut the sleeve member 54 and will, in effect, lock the inner tongue member 88 in any selected vertical relationship with respect thereto. This exemplary structure is best shown in FIG. 10 and will be described in greater detail hereinafter. It should be clearly understood that this particular type of constriction means, while advantageous, is not to be construed \as specifically limiting the invention thereto. Actually, various other types of constriction means and/ or locking means may be employed in lieu thereof.

Each of the two mounting post means 42 also comprises a vertically telescopic structure (which is, effectively, a part of the vertical extension means 86) capable of being vertically extended and retracted in order to make possible the previously described vertical extension and subsequent retraction of the upper structural wall 33 and top wall 26 from the lowermost positions thereof as shown in solid lines in FIGS. 7 \and 8 into the uppermost positions thereof as shown in broken lines in FIGS. 7 and 8 or into any position therebetween. Of course, it should be understood that the reverse, return, or retraction movement is also made possible by the previously described extension means 86 plus the telescopic structure of the two mounting post means 42.

In the exemplary form illustrated, it will be noted that each mounting post means 42 includes a lower sleeve portion 114 which is fastened to, or is integnal with, the horizontal lower sleeve 48 and which extends upwardly through the slot 55 in the lower horizontal tongue member 52. The upper element of each mounting post means 4-2 comprises a post 116 which is fastened at its top end to, or is integral with, the upper sleeve 48 and which extends downwardly through the upper slot 55 in the upper horizontal tongue member 52. It will be noted that top and bottom screws 113 are threaded through the outside top and bottom walls 26 and 28 into opposite ends of the corresponding upper and lower elements 116 and 114 of each mounting post means 42 in order to firmly fasten the upper and lower walls in place.

For exemplary purposes, the right one of the two constriction means of the vertical extension means 86 is shown in FIG. 10 in a laterally exploded relationship, and it should be understood that the left one is of identical construction, although positionally reversed and, therefore, will not be independently described in detail in a manner similar to the following detailed description of the exemplary right constriction means best shown in FIG. 10.

Said constriction means 90 includes the previously mentioned manually gnaspable operating or knob portion 92 connected to the previously mentioned inwardly laterally extending shaft portion 94, which is adapted to exend through the vertical slot 96 in the sleeve 54 and through the hole 98 in the tongue member 88 into a position extending inwardly thereof. The tongue member 88 has a spring member 190 fastened thereto by having coiled opposite ends 102 provided with rivets or screws 104 adapted to extend into, and be fastened with respect to, corresponding fastening holes 106 in the tongue member 88, thus firmly mounting the spring .100 with the central portion thereof lying substantially across the throughhole 98 in the tongue member 88 in a position such as to fit into the correspondingly positioned, shaped, and sized end slot 108 in the round shaft 94 extending through the hole 98 of the tongue member 88. The slot 108 effectively rotates, or changes its plane, along the length of the shaft 94 in what might be termed a helically twisted manner at each end terminus of the slot 108 and terminates in a rear inner retention portion 110, one end terminus of which is clearly shown in FIG. 10. It is obvious that rotation of the knob 92 in a clockwise direction (usually through approximately ninety degrees) as one views it from the right exterior side of the complete device such as seen in FIG. 1, for extarnple, will cause the central portion 100 of the spring to ride outwardly angularly along the helically twisting groove or slot 108 toward the rear retention portion 110 thereof which effectively applies outwardly directed force to the central portion of the spring 100 and thus causes an inward biasing of the inner fiat surface contact portion 112 of the actuating member 92 against the outer surface of the sleeve 54 so as to positively frictionally lock the entire vertical extension means 86 in whatever relative positioning of the various parts may exist at that time. This locked relationship is shown in all of the figures except FIGS. 7, 10, land 8 (in solid lines). Conversely, it is clear that oppositely directed counterclockwise rotation of the actuating knob 92 from the clockwise extreme locked relationship just described will reduce or release the tension on thespring 100 and thus reduce the force existing between the frictional contact surface 112 and the outside of the sleeve 54 and thus effectively free the sleeve 54 and the tongue 88 for relative vertical extension movement thereof from a position such as is shown in solid lines in FIGS. 7 and 8 toward an extended position such as is shown in broken lines in FIGS. 7 and 8. This unlocked relationship is shown in FIGS. 7 and 8.

-While the exemplary constriction means 9!] provides a highly advantageous and simple arrangement, the invention is not limited thereto, and various other types of constriction means and/ or locking means may be employed in lieu thereof.

It should be understood that the figures and the specific description thereof set forth in this application are for the purpose of illustrating the present invention and are not to be construed as limiting the present invention to the precise and detailed specific structures shown in the figures and specifically described hereinbefore. Rather, the real invention is intended to include virtually all substantially equivalent constructions and/or methods embodying the basic teachings and inventive concept of the present invention.

I claim:

1. A binding and locking device for holding sheets of material, comprising: end wall means provided with a pair of spaced substantially parallel top and bottom walls similarly projectingly connected with respect to said end wall means in substantially perpendicular relationship with respect thereto and together therewith defining receiving recess means; a pair of spaced substantially parallel auxiliary inner walls positioned im mediately inside of said top and bottom walls and substantially vertically enclosing said receiving recess means therebetween; mounting means comprising mounting and fastening post means connected between said auxiliary walls and spaced outwardly from said end wall means and substantially parallel thereto so as to extend vertically through said receiving recess means for controllably disengageable attachment with respect to at least one sheet of material having an inner fastening edge provided with inwardly and laterally directed groove means having an inner offset retaining portion retainingly receivingly cooperable with said fastening post means; transversemovement-immobilizing means for locking each fastening edge of each sheet of material with its inner offset retaining portion retainingly receiving said fastening post means, said transverse-movement-immobilizing means comprising side wall abutment means slidably mounted with respect to said auxiliary inner walls for controllable slidable inward movement into an abutting retracted locked position and relationship with respect to a side part of a fastening edge of a sheet of material toward which an inner offset retaining portion of a groove means thereof extends whereby to prevent the sheet of material from being transversely moved in a manner such as to move the inner offset retaining portion thereof transversely away from said fastening post means, said side Wall abutment means also being slidably mounted for controllable slidable outward extension movement away from an abutted side part of a fastening edge of a sheet of material into an extended unlocked position and relationship to allow an inner offset retaining portion of a groove means thereof to be slidably moved away from said fastening post means for disengagement of the fastening edge of the sheet of material therefrom; and pressure-applying keeper means cooperable for pressing vertically on an outer surface of an inner fastening edge of a thin sheet of material for normally eliminating vertical freedom of movement thereof when said transverse-movement-immobilizing means is in retracted locking relationship, said keeper means being mounted by one of said auxiliary walls in a manner effectively cooperable with respect to said transverse-movement-immobilizing means for causing vertical retraction of said keeper means when said transversemovement-immobilizing means is extended into unlocked relationship; said auxiliary walls being provided with additional side wall means connected therebetween at similar ends thereof opposite from the side wall abutment means comprising the transverse-movement-immobilizing means, with each of said side wall means being provided with vertical extension means allowing controlled vertical movement it either an extension or retraction manner of said auxiliary walls in a manner such as to correspondingly increase or decrease the vertical depth of said receiving recess means, said vertical extension means comprising vertical telescopic means provided with controllably operable constriction means for locking said vertical telescopic means in a manner such as to prevent any vertical extension or retraction thereof; said end wall means including at least two separate vertically relatively slidable elements to allow for vertical extension and retraction thereof; said transversemovement-immobilizing side wall abutment means and said auxiliary walls being effectively provided with transversely directed telescopic extension and retraction coupling means for making possible said extending and retracting movement thereof with respect to the remainder of said auxiliary walls into said extended unlocked relationship and said retracted locked relationship, respectively.

2. A device as defined in claim 1, positively including in combination therewith at least one sheet of material having an inner fastening edge provided with inwardly and laterally directed groove means having an inner offset retaining portion retainingly receivingly cooperable with said fastening post means.

3. A device as defined in claim 1, positively including in combination therewith a plurality of similar thin sheets of material having similarly inner-positioned fastening edges, each provided with inwardly and laterally directed groove means having an inner offset retaining portion receivingly and retainingly cooperable with said fastening post means; said pressure-applying keeper means pressing vertically downwardly on the top surface of an uppermost one of said plurality of thin sheets of material mounted on said fastening post means for normally preventing the vertical separation of the inner-positioned fastening edges thereof when the transverse-movement-immobilizing means is in retracted locking relationship.

References Cited UNITED STATES PATENTS 561,670 6/1896 Kosby 129-18 603,500 5/1898 Edson.

682,339 9/1901 Opalla 12913 X 1,661,524 3/1928 Baumer 129-5 X 1,822,310 9/1931 Osman 12913 X 1,874,092 8/1932 Finley 129-13 2,010,418 8/1935 Shedd 129l8 FOREIGN PATENTS 26,310 1911 Great Britain. 681,370 10/ 1952 Great Britain. 652,926 5/ 1951 Great Britain.

JEROME SCHNALL, Primary Examiner. 

